EP0253560A1 - Méthode de copiage électrophotographique et papier isolant pour l'utilisation dans cette méthode - Google Patents

Méthode de copiage électrophotographique et papier isolant pour l'utilisation dans cette méthode Download PDF

Info

Publication number
EP0253560A1
EP0253560A1 EP87306022A EP87306022A EP0253560A1 EP 0253560 A1 EP0253560 A1 EP 0253560A1 EP 87306022 A EP87306022 A EP 87306022A EP 87306022 A EP87306022 A EP 87306022A EP 0253560 A1 EP0253560 A1 EP 0253560A1
Authority
EP
European Patent Office
Prior art keywords
black
paper
insulating
toner
images
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP87306022A
Other languages
German (de)
English (en)
Other versions
EP0253560B1 (fr
Inventor
Shuji Komura
Nobuyasu Honda
Masanori Fujii
Yusuke Ishitani
Shunsuke Ogami
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Kyocera Mita Industrial Co Ltd
Original Assignee
Mita Industrial Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from JP16138986A external-priority patent/JPS6317463A/ja
Priority claimed from JP61164263A external-priority patent/JPS6319668A/ja
Priority claimed from JP23079986A external-priority patent/JPH0677160B2/ja
Priority claimed from JP23080086A external-priority patent/JPS6385573A/ja
Priority claimed from JP23080186A external-priority patent/JPS6385574A/ja
Application filed by Mita Industrial Co Ltd filed Critical Mita Industrial Co Ltd
Publication of EP0253560A1 publication Critical patent/EP0253560A1/fr
Application granted granted Critical
Publication of EP0253560B1 publication Critical patent/EP0253560B1/fr
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G13/00—Electrographic processes using a charge pattern
    • G03G13/22—Processes involving a combination of more than one step according to groups G03G13/02 - G03G13/20
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G7/00—Selection of materials for use in image-receiving members, i.e. for reversal by physical contact; Manufacture thereof
    • G03G7/006—Substrates for image-receiving members; Image-receiving members comprising only one layer
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G7/00—Selection of materials for use in image-receiving members, i.e. for reversal by physical contact; Manufacture thereof
    • G03G7/006—Substrates for image-receiving members; Image-receiving members comprising only one layer
    • G03G7/0066—Inorganic components thereof
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G7/00—Selection of materials for use in image-receiving members, i.e. for reversal by physical contact; Manufacture thereof
    • G03G7/006—Substrates for image-receiving members; Image-receiving members comprising only one layer
    • G03G7/0073—Organic components thereof

Definitions

  • This invention relates to an electrophotographic copying method for providing copies in which the light and dark areas of images and background of an original are formed in a reverse manner and also relates to black insulating paper for electrophotography which can be used in such method.
  • this invention relates to a copying method of such type in which an ordinary positive-image copying apparatus is used.
  • positive-image copying systems and negative-image copying systems are employed.
  • a positive-image copying system which is usually used, a positive original having dark images, letters or the like, and a bright background which represents the area of the original excluding the area in which the images are formed is used, latent images corresponding to the images of the original are formed on a photosensitive member, and then developed by a black toner.
  • the developed images are transferred to transfer paper, for example a white paper, and then fixed thereon, so that a positive copy having dark images and a bright background as in the original is obtained.
  • a negative-image copying system by using a negative original such as a microfilm having bright images and a dark background or by forming images of light beams emitted from a laser or LED array, a latent image of the background is formed, and thereafter the areas of a photosensitive member other than that of.the latent image are developed by a black toner, the developed toner images are transferred to transfer paper, for example a white paper , and fixed thereon, whereby, the light and dark areas of images and of background are reversed to obtain a positive copy.
  • transfer paper for example a white paper
  • the first system uses a photosensitive member which can be charged positively or negatively, a charger which can positively or negatively charge the photosensitive member, and a toner having a triboelectrification characteristic of a predetermined polarity.
  • a photosensitive member which can be charged positively or negatively
  • a charger which can positively or negatively charge the photosensitive member
  • a toner having a triboelectrification characteristic of a predetermined polarity.
  • the other method uses a photosensitive member which can be charged with a predetermined polarity and a toner which can be charged positively or negatively.
  • the photosensitive member is charged, and exposed to the images of an original to form, on the member, latent images which correspond to the images of the original.
  • the latent images are developed by a toner which has been charged with a polarity opposite to that of the latent images, without applying a bias voltage to the developing region, and, when reversed images are to be formed, the background area (the area other than the areas in which the latent images are formed) is developed by a toner which has been charged with a polarity the same as that of the photosensitive member, while applying a bias voltage to the developing region, whereby reverse development is conducted.
  • two kinds of toners must be used for developing positive images and reversed images, and, according to the situation, electrical control such as application of a bias voltage to a developing region must be conducted. For these reasons, it is difficult to construct and control a copying apparatus having both a positive-image copying system and a reversed-image copying system.
  • an object of this invention disclosed herein is to provide an electrophotographic copying method which can produce reversed images from an original without requiring a special device or a control means.
  • the electrophotographic copying method of this invention comprises: using a copying apparatus having a positive-image copying system; forming toner images with a colored toner; transferring the toner images to a colored paper of a different color to said colored toner; and fixing the transferred images to the paper, thereby providing a copy in which the lightness and darkness of images and the background of an original are formed in a reverse manner.
  • the colored toner is a white toner.
  • the colored paper is preferably obtained by forming an area of a desired color on a transfer paper by use of an electrophotographic copying apparatus.
  • the colored paper there can be used as the colored paper a black insulating paper with a surface specific resistance of 10 9 9 or more and a volume specific resistance of 5 x 10 9 Q.cm or more.
  • This invention thus also provides black insulating paper for electrophotography to which toner images produced by a colored toner are to be transferred and fixed to form images in which the lightness and darkness of images and background are reversed by using a positive-image electrophotographic copying apparatus, the surface specific resistance of said paper being 10 9 9 or more and the volume specific resistance of said paper being 5 x 10 9 n.cm or more.
  • said black insulating paper is obtained by mixing an insulating black pigment and a beaten pulp in a step in which mixing bf said pulp with one or more of inter alia, a sizing agent, a filler agent and dyes, takes place.
  • said black insulating paper may be obtained by applying an insulating transparent resin to conductive black paper or by impregnating conductive black paper with the resin.
  • the black insulating paper may also be obtained by laminating an insulating transparent film on conductive black paper.
  • said black insulating paper is obtained by printing or applying an insulating black pigment to white paper, or impregnating white paper with the pigment.
  • the insulating black pigment when used is preferably a black toner having preferably a volume mean particle size of 5 11 m or less.
  • the insulating black pigment may be obtained by coating a conductive black pigment with a transparent insulating resin.
  • the conductive black pigment itself is preferably selected from carbon black, graphite, cyanine black, CuCr 2 O 4 and CuFe204-CuMn204.
  • This invention meets the aforementioned object and provides an electrophotographic copying method for easily obtaining an easy to read positive copy from a negative original. Even if documents produced by a printer or a facsimile apparatus of a thermal transfer type are lost, the copying method of this invention can produce positive images by copying a transfer film having negative images which have been used in producing the documents, thereby allowing the documents to be reproduced.
  • This invention also provides an electrophotographic copying method which can obtain a positive copy from a negative original, and, therefore, is applicable in the fields of design, advertising and printing.
  • the electrophotographic copying method of this invention can easily and reliably produce reversed images on an ordinary white paper.
  • the black insulating paper of this invention is suitable for use in the above-mentioned methods.
  • the black insulation paper for electrophotography can be made by a simple process and gives a clear image without the danger of wrinkling, curling or the like.
  • the black insulating paper of this invention is very economical.
  • the electrophotographic copying method of this invention can be performed with a conventional electrophotographic copying apparatus which has a positive-image copying system.
  • a positive copy having dark images and a bright background is obtained from a negative original having bright images and a dark background with, for example, an electrophotographic copying apparatus having a positive-image copying system
  • a colored toner and colored paper are used, the color of the toner being of a relatively low density, and the color of the paper being of a density higher than that of said colored toner.
  • the electrophotographic copying apparatus in which the colored toner and colored paper are set operates in a usual manner as follows: a latent image formed on the photosensitive member, corresponding to the background of the origin'al,is developed by the colored toner the color of which is of a relatively low density, the resulting toner image being transferred to the colored paper the color of which is of a density higher than that of said colored toner, after which the toner image on the colored paper is fixed, thereby obtaining a copy in which the light and darkness of the original are reversed.
  • a reversed copy can be obtained without a special device or electrical control.
  • a white toner is suitably used as the colored toner for developing latent images.
  • Colored paper to which toner images formed by a colored toner are to be transferred and fixed can be obtained by forming a region of a desired color on the paper with a colored toner (for example, a black toner).
  • an ordinary positive-image copying apparatus is used.
  • the colored toner for example, a black toner which is used in a conventional copying apparatus is used.
  • a completely black original is placed on a document table, alternatively nothing is placed on the table with the table cover kept open.
  • copying is done under usual conditions for copying with a black toner.
  • colored paper i.e., white paper one face of which is coated in its entirety with the black toner fixed on it
  • White transfer paper useful in a copying apparatus of the electrostatic transfer type has insulating properties sufficient for being electrostatically transferred.
  • the toner to be used in the copying apparatus is changed from black toner to white toner.
  • the colored paper is set as transfer paper in g the copying apparatus, a negative original from which a reversed copy is to be formed is placed on the document table, and thereafter copying is conducted.
  • a positive copy is obtained in which the area thereof corresponding to the background of the original is colored in white by the white toner and the areas corresponding to the images of the original are colored in black by the black-colored paper.
  • Many recent copying apparatus have a developing unit which can be replaced.
  • a plurality of developing units each of which contains a toner of a color different from each other can be used, and copies by a different color can be obtained by using each of the units.
  • two developing units are prepared, one containing a black toner and the other containing a white toner.
  • colored paper is made using the developing unit containing a black toner, and thereafter the developing unit is replaced by the other developing unit containing a white toner,. and, for example, a positive original which is to be copied is placed on a document table.
  • a positive copy having dark images and a bright background can be obtained from a negative original having bright images and a dark background, and also a negative copy having bright images and a dark background can be obtained from a positive original having dark images and a bright background.
  • the colored paper which constitutes the background of a copy is not limited to being white, and may be formed using a toner of a pale color such as yellow, or light blue, and as the colored toner which constitutes images such as letters in a positive copy, in addition to a black toner, a toner of a dark color such as red, blue, or green can be used.
  • the colored toner which constitutes images of the copy is composed of a white toner or a toner of a pale color such as yellow, or light blue
  • the colored toner which constitutes the background is composed of a black toner or a toner of a dark color such as red, blue, or green.
  • the colored paper in addition to a transfer paper having a colored region formed by a colored toner as described above, it is also possible to use a black insulating paper which has a surface specific resistance of 10 9 ⁇ or more and a volume specific resistance of 10 9 ⁇ cm or more, because of the reasons mentioned below.
  • the amount of the electric resistance of a transfer paper greatly affects the transfer efficiency of toner images or latent images and also the quality of the copied images.
  • the electric resistance of a transfer paper is not sufficiently high, charges from a transfer corotron or a bias roll flow into the ground through the transfer paper, which prevents the formation of an electric field sufficient for transfer, and, therefore, the transfer efficiency is reduced.
  • the electric resistance of a transfer paper is too low, charges will leak via the transfer paper to lower the level of the transferring field, thereby producing voids in the toner images.
  • the relationship between the surface specific resistance (Q) of a transfer paper and the transfer efficiency (%) is shown in Figure 1.
  • black insulating paper having a surface specific resistance of 109 Q or more and a volume specific resistance of .5 x 10 9 ⁇ -cm or more can be used as colored paper in the method of this invention. If black insulating paper having a surface specific resistance of less than 109D or a volume specific resistance of less than 5 x 10 9 ⁇ .cm is used in copying, the transfer efficiency will decrease and voids in the toner images will occur, and, therefore, resulting copies will be unclear.
  • the black insulating paper can be made, for example, by mixing an insulating black pigment (e.g., a black toner) with pulp in a known process of manufacturing paper.
  • an insulating black pigment e.g., a black toner
  • pulp is suspended in water, and then beaten.
  • the beaten pulp is mixed with a sizing agent, filler agent, dyes, etc., and then made into paper.
  • the paper is rolled or cut to form rolled paper or cut paper.
  • the insulating black pigment is added together with a sizing agent, filler agent, dyes, etc. into the beaten pulp.
  • the insulating black pigment can be obtained by coating a conductive black pigment such as carbon black, graphite, cyanine black, CuCr 2 O 4 and CuFe 2 O 4 -CuMn 2 O 4 with insulating transparent resin.
  • a conductive black pigment such as carbon black, graphite, cyanine black, CuCr 2 O 4 and CuFe 2 O 4 -CuMn 2 O 4
  • the insulating transparent resin are polystyrene; styrene copolymers such as styrene-butadiene copolymer and styrene-acrylic copolymer; polyethylene; ethylene copolymers such as ethylene-vinyl acetate copolymer, and ethylene-vinyl alcohol copolymer; phenolic resin; epoxy resin; allylphthalate resin; polyamide resin; polyester resin; and maleic acid resin.
  • the conductive black pigment can be coated by the same method as is used in manufacturing conventional toners for electrophotography.
  • a conductive black pigment and an insulating transparent resin are mixed in a mixer, and then the mixture is heated and fused in a heated roll mill to be kneaded.
  • the kneaded product is pulverized in a feather mill or a jet mill, and the resulting powder is classified to obtain insulating black pigment of the desired particle size. It is preferable to conduct the classification so that the volume mean particle size of obtained pigment is 10 ⁇ m or less. If an insulating black pigment having a mean particle size larger than 10 ⁇ m is used in electrophotography, a clear copy will not be obtained.
  • the insulating black pigment is a black toner.
  • the black toner can be prepared by a method for manufacturing a conventional toner for electrophotography as mentioned above.
  • the above-mentioned insulating transparent resin can be used also as a binder resin.
  • the black coner thus obtained preferably has a volume mean particle size of 5 ⁇ m or less.
  • finely pulverized black toner (with a volume mean particle size of 5 ⁇ m or less) can be separately obtained, and the use of the sepa-rated black toner as the insulating black pigment is economical.
  • the black insulating paper can be obtained also by applying an insulating transparent resin to conductive black paper or by impregnating the resin into the paper.
  • the insulating transparent resin the same resin which is used in coating the conductive black pigment can be used.
  • the resin is, in general, dissolved in an appropriate solvent, and then the solution is applied to or impregnated into conductive black paper.
  • the black insulating paper can be obtained also by laminating an insulating transparent film on conductive black paper.
  • Useful examples of the insulating transparent film are films made from polyethylene terephthalate, poly-4-methylpentene-l, polyolefin resin or the like.
  • the insulating transparent film can be made by forming a film of any of the above-mentioned resins on both sides of conductive black paper, using a laminating method such as an extrusion laminating method.
  • the black insulating paper can also be made by printing or applying an insulating black pigment on white paper or by impregnating such a pigment into white paper.
  • a black toner can be suitably used.
  • a black toner having a volume mean particle size of 5 pm or less is preferably used.
  • An example of the white paper is conventional transfer paper which is used in an electrophotographic copy.
  • the insulating black pigment also can be prepared by coating a conductive black pigment such as carbon black, graphite, etc., with an insulating transparent resin, as described above.
  • the resin such as those listed above can be used.
  • the black insulating paper obtained in this way is used in a conventional electrophotographic copying process, problems of bad transferring will not arise. Therefore, the black insulating paper can be used also in the method of this invention in which a reversed copy is formed with a conventional copying apparatus. An example of the method of this invention in which said black insulating paper is used is described below.
  • the white toner fixed to the colored paper must cover or conceal the colored paper. It is preferable that such a white toner has a concealment index of 5 or more (as evaluated by the method described below) so that the color of the colored transfer paper (e.g., colored in black) is sufficiently concealed.
  • a black toner Using a black toner, an original, one face of which is black in its entirety, is copied onto white transfer paper so that the reflection density of the obtained black paper is 1.5.
  • a reflection density meter TC-6D (made by Tokyo Denshoku) is used.
  • images are formed by a white toner on the colored transfer paper to which a black toner has been fixed.
  • the reflection density of the images formed by the white toner is X
  • the concealment index is evaluated by the following formula which has been proposed by the present inventors:
  • a white toner useful as a colored toner in this invention should have a concealment index of 5 or more as calculated above.
  • a white toner may contain a binding resin, white coloring agent, and any other compounding ingredients such as an antistatic agent and a release agent.
  • Their composition ratios are not restricted unless they exert a bad influence on the tone of the toner.
  • the weight ratio of a white coloring agent and a binding resin is in the range of 2:100 to 35:100 If the portion of the white coloring agent is below this range, the concealment index of the white toner obtained against a colored paper will be insufficient. If the portion is above this range, the triboelectrification property of the white toner will be poor, and spent toners will be more readily generated, thereby reducing the life span of the developing agent.
  • white coloring-agent for the white toner examples include zinc.white, titanium dioxide, tin oxide, antimony white, zinc sulfide, zinc oxide, barium carbonate, clay, silica, white carbon, talc, alumina, baryte, etc.
  • binding resin for the white toner are various resin materials which are known for use as binding resins for toners in electrophotography.
  • An antistatic agent which can be used for the white toner is any appropriate known material which does not produce a deleterious effect on the tone of a white toner.
  • antistatic agents which inhibit positive charging are organic compounds having basic nitrogen such as basic dyes, aminopyrine, pyrimidine compounds, polynuclear polyamine compounds, aminosilanes, and filler agents the surface of which is treated by these substances.
  • antistatic agents wich inhibit negative charging are compounds containing carboxyl groups such as a metal chelate of an alkylsalicylic acid. These antistatic agents are preferably used in a 1 to 10% proportion by weight in a toner.
  • release agents for the white toner are silicone oil, olefin resins of low molecular Weight, and various kinds of waxes.
  • the white toner can be obtained by the following processes: the above-mentioned components are fused and kneaded, and after cooling the product is pulverized and classified. Also, the white toner can be obtained by dispersing the above-mentioned components in a resin solution and by applying it in a spray formulation whereby a granulate is produced.
  • a reversed copy is obtained from an original which is a transparent sheet with images formed thereon, it being possible to place the original on a document table and expose it from the rear side (which is opposite the face of the table) so as to provide a copy having excellent reproducibility.
  • the exposure is conducted in the direction perpendicular to the surface of the original, whereby the clarity of the images can be improved.
  • FIG. 3 shows an example of a copying apparatus which can be used in performing this method.
  • the copying apparatus is provided with a photosensitive drum (hereinafter, referred as "drum") 10 which is disposed in the center of the apparatus and can rotate in the direction shown by an arrow A.
  • drum photosensitive drum
  • the following devices are disposed successively: a charger 20 for uniformly charging the drum 10; an exposure system 30 for exposing an original 37 placed on a document table 35 to form latent images corresponding to images of the original; a surface exposure device 80 which is disposed at the rear side of the original 37, independently from the exposure system 30; a developing device 40 for developing toner images from the latent images formed on the drum 10; a transfer device 50 for transferring the toner images on the drum 10 to transfer paper; a separator 55 for separating the transfer paper from the drum 10; and a cleaning device 60 for removing residual toner on the drum 10 after the transfer of the toner images to the transfer paper.
  • the surface exposure device 80 disposed at the rear side of the original 37 comprises, as shown in Figure 4, a wide exposure surface 81 and a glass screen 82.
  • the device 80 is mounted so that the exposure surface 81 covers the original 37. After the toner images on the transfer paper are fixed by a fixing device 70, the transfer paper is discharged.
  • the exposure of the images is conducted perpendicularly from the rear side of the original 37 so that the light corresponding to the original 37 is transmitted perpendicularly.
  • the transmitted light is introduced to the drum 10 vi-a a movable lens 32 and mirrors 33 to form latent images. For this reason, the obtained images are clear.
  • the above-listed agents were mixed for 5 minutes in a Henshel mixer FM10B (made by Mitsui Miike). Then the mixture was fused and kneaded in a twin-screw extruder PCM-30 (made by Ikegai Tekko) and allowed to stand for cooling. The kneaded product was coarsely pulverized by a cutting mill, then finely pulverized by a jet pulverizer, and classified to obtain a white toner having a volume mean particle size of 11 to 12 ⁇ m.
  • the white developer was charged into a copying apparatus (DC-111 made by Mita Industrial Co., Ltd.).
  • As transfer paper three kinds of paper which were colored in black, red and navy blue, respectively were used.
  • a negative original having bright images and a dark background was placed on the document table, and copying operations were conducted.
  • Clear positive reversed copies were obtained in which the background of the original were developed by the white toner and the images were displayed by the color (black, red or navy blue) of the colored paper.
  • the values of the reflection density of the images developed by the white toner and those of the background displayed by the surface of the colored paper are shown in the following table.
  • Example 1 The above-listed materials were premixed in the Henshel mixer of Example 1. Then the mixture was fused and kneaded in the twin-screw extruder of Example 1 and allowed to stand for cooling. The kneaded product was coarsely pulverized by a cutting mill, then finely pulverized by anultrasonic jet mill PJM-100 to obtain an insulating black pigment having a volume mean particle size of 8 ⁇ m.
  • the insulating black pigment was mixed, into beaten pulp together with a sizing agent, filler agent, dyes, etc. Then, by a well known process of paper manufacture, black insulating paper was made.
  • the black insulating paper obtained had a surface specific resistance of 1.5 x 10 10 ⁇ , and a volume specific resistance of 2.1 x 10 11 ⁇ cm.
  • the white toner made in in Example 1 Using the black insulating paper as transfer paper, the white toner made in in Example 1, and a usual positive-image copying apparatus (DC-111 made by Mita Industrial Co., Ltd.), white images were formed on the black insulating paper. The resulting white images were clear, and no wrinkles or curls were observed in the images.
  • DC-111 made by Mita Industrial Co., Ltd.
  • Example 2 The same procedures as those of Example 2 were conducted except that 20 parts by weight of carbon black and 2.5 parts by weight of polypropylene of low molecular weight (Biscol 550P made by Sanyo Kasei) were used to obtain a black toner having a volume mean particle size of 9 ⁇ m.
  • the black toner was mixed into beaten pulp, together with a sizing agent, filler agent, dyes etc.
  • the obtained black insulating paper had a surface specific resistance of 1.5 x 10 10 ⁇ , and a volume specific resistance of 2.6 x 10 11 ⁇ cm.
  • the white toner made in Example 1 Using the black insulating paper as transfer paper, the white toner made in Example 1, and a conventional positive-image copying apparatus (DC-111 made by Mita Industrial Co., Ltd.), white images were formed on the black insulating paper. The resulting white images were clear, and no wrinkles or curls were observed in the images.
  • DC-111 made by Mita Industrial Co., Ltd.
  • Black toner obtained in the same manner as that in Example 3 was further classified by an alpine classifier to obtain a black toner having a volume mean particle size of 3.5 ⁇ m.
  • the black toner was mixed into beaten pulp, together with a sizing agent, filler agent, dyes etc.
  • the black insulating paper obtained had a surface specific resistance of 1.8 x 10 10 ⁇ , and a volume specific resistance of 3.2 x 10 11 ⁇ cm.
  • the white toner made in Example 1 Using the black insulating paper as transfer paper, the white toner made in Example 1, and a conventional positive-image copying apparatus (DC-111 made by Mita Industrial Co., Ltd.), white images were formed on the black insulating paper. The resulting white images were clear, and no wrinkles or curls were observed in the images.
  • DC-111 made by Mita Industrial Co., Ltd.
  • the ,black insulating paper obtained had a surface specific resistance of 1.2 x 10 10 ⁇ , and a volume specific resistance of 1.8 x 10 11 ⁇ cm.
  • the white toner made in Example 1 Using the black insulating paper as transfer paper, the white toner made in Example 1, and a conventional positive-image copying apparatus (DC-111 made by Mita Industrial Co., Ltd.), white images were formed on the black insulating paper. The resulting white images were clear, and no wrinkles or curls were observed in the images.
  • DC-111 made by Mita Industrial Co., Ltd.
  • Example 5 The same procedures as those of Example 5 were carried out except that a methanol solution of polyvinyl pyrrolidone (20% by weight) was used instead of the methanol solution of polyvinyl butyral (20% by weight) to obtain black insulating paper.
  • the black insulating paper obtained had a surface specific resistance of 8.0 x 10 9 ⁇ , and a volume specific resistance of 1.5 x 10 11 ⁇ cm.
  • the white toner made in Example 1 Using the black insulating paper as transfer paper, the white toner made in Example 1, and a conventional positive-image copying apparatus (DC-111 made by Mita Industrial Co., Ltd.), white images were formed on the black insulating paper. The resulting white images were clear, and no wrinkles or curls were observed in the images.
  • DC-111 made by Mita Industrial Co., Ltd.
  • Example 5 The same procedures as those of Example 5 were carried out except that a methanol solution of a copolymer of acrylic ester and methacrylic ester (20% by weight) was used instead of the methanol solution of polyvinyl butyral (20% by weight) to obtain black insulating paper.
  • the black insulating paper obtained had a surface specific resistance of 3.0 x 10 10 ⁇ , and a volume specific resistance of 5.2 x 10 11 ⁇ cm.
  • the white toner made in Example 1 Using the black insulating paper as transfer paper, the white toner made in Example 1, and a conventional positive-image copying apparatus (DC-111 made by Mita Industrial Co. Ltd.), white images were formed on the black insulating paper. The resulting white images were clear, and no wrinkles or curls were observed in the images.
  • DC-111 made by Mita Industrial Co. Ltd.
  • the insulating black pigment obtained in Example 2 was dissolved in toluene in a concentration of 25% by weight.
  • the solution obtained was applied to conventional white transfer paper for electrophotography in a thickness of 5 ⁇ m.
  • the black insulating paper obtained had a surface specific resistance of 4.8 x 10 10 ⁇ , and a volume specific resistance of 5.6 x 10 11 ⁇ cm.
  • the white toner made in Example 1 Using the black insulating paper as transfer paper, the white toner made in Example 1, and a conventional positive-image copying apparatus (DC-111 made by Mita Industrial Co., Ltd.), white images were formed on the black insulating paper. The resulting white images were clear, and no wrinkles or curls were observed in the images.
  • DC-111 made by Mita Industrial Co., Ltd.
  • the insulating black pigment obtained in Example 3 was dissolved in toluene in a concentration of 30% by weight. The solution was applied to conventional white transfer paper for electrophotography in a thickness of 5 ⁇ m.
  • the black insulating paper obtained had a surface specific resistance of 1.3 x 10 10 ⁇ , and a volume specific resistance of 2.4 x 10 11 ⁇ cm.
  • the white toner made in Example 1 Using the black insulating paper as transfer paper, the white toner made in Example 1, and a conventional positive-image copying apparatus (DC-111 made by Mita Industrial Co., Ltd.), white images were formed on the black insulating paper. The resulting white images were clear, and no wrinkles or curls were observed in the images.
  • DC-111 made by Mita Industrial Co., Ltd.
  • the black toner obtained in Example 4 was dissolved in toluene in a concentration of 30% by weight.
  • the solution was applied to a conventional white transfer paper for electrophotography in a thickness of 5 ⁇ m.
  • the black insulating paper obtained had a surface specitic resistance of 1.4 x 1010 ⁇ , and a volume specific resistance of 2.8 x 10 11 ⁇ cm.
  • the white toner made in Example 1 Using the black insulating paper as transfer paper, the white toner made in Example 1, and a conventional positive-image copying apparatus (DC-111 made by Mita Industrial Co., Ltd.), white images were formed on the black insulating paper. The resulting white images were clear, and no wrinkles or curls were observed in the images.
  • DC-111 made by Mita Industrial Co., Ltd.
  • Example 2 The same procedures as those of Example 1 were carried out, except that a transparent negative film (a transparent sheet) was used and the exposure was done from the rear side of the film to form reversed images.
  • the images obtained were clear and excellent in reproducibility.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Chemical & Material Sciences (AREA)
  • Inorganic Chemistry (AREA)
  • Developing Agents For Electrophotography (AREA)
  • Paper (AREA)
EP19870306022 1986-07-08 1987-07-08 Méthode de copiage électrophotographique et papier isolant pour l'utilisation dans cette méthode Expired - Lifetime EP0253560B1 (fr)

Applications Claiming Priority (10)

Application Number Priority Date Filing Date Title
JP161389/86 1986-07-08
JP16138986A JPS6317463A (ja) 1986-07-08 1986-07-08 電子写真法における複写方法
JP164263/86 1986-07-11
JP61164263A JPS6319668A (ja) 1986-07-11 1986-07-11 電子写真複写方法
JP230801/86 1986-09-29
JP230799/86 1986-09-29
JP230800/86 1986-09-29
JP23079986A JPH0677160B2 (ja) 1986-09-29 1986-09-29 電子写真用黒色絶縁紙およびそれを用いた電子写真複写方法
JP23080086A JPS6385573A (ja) 1986-09-29 1986-09-29 電子写真用黒色絶縁紙およびそれを用いた電子写真複写方法
JP23080186A JPS6385574A (ja) 1986-09-29 1986-09-29 電子写真用黒色絶縁紙およびそれを用いた電子写真複写方法

Publications (2)

Publication Number Publication Date
EP0253560A1 true EP0253560A1 (fr) 1988-01-20
EP0253560B1 EP0253560B1 (fr) 1991-07-03

Family

ID=27528262

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19870306022 Expired - Lifetime EP0253560B1 (fr) 1986-07-08 1987-07-08 Méthode de copiage électrophotographique et papier isolant pour l'utilisation dans cette méthode

Country Status (2)

Country Link
EP (1) EP0253560B1 (fr)
DE (1) DE3771139D1 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6114077A (en) * 1998-07-31 2000-09-05 Agfa-Gevaert, N.V. White toner composition
EP1134622A2 (fr) * 1995-04-07 2001-09-19 Indigo N.V. Toner et substrat plastique

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2044780A1 (fr) * 1969-09-11 1971-03-18
DE2830001A1 (de) * 1977-07-07 1979-01-25 Westinghouse Electric Corp System zur erstellung einer strichzeichnung von einem abgetasteten bild
GB2067306A (en) * 1980-01-07 1981-07-22 Bell & Howell Co Apparatus for and Methods of Making Bimodal Electrophotographic Copies
EP0084693A1 (fr) * 1982-01-19 1983-08-03 Agfa-Gevaert N.V. Toner fusible pouvant être attiré électrostatiquement
EP0162577A2 (fr) * 1984-04-17 1985-11-27 Hitachi Chemical Co., Ltd. Procédé de production de toners pour l'électrophotographie

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6026225B2 (ja) * 1977-07-12 1985-06-22 コニカ株式会社 色画像再現方法及び装置

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2044780A1 (fr) * 1969-09-11 1971-03-18
DE2830001A1 (de) * 1977-07-07 1979-01-25 Westinghouse Electric Corp System zur erstellung einer strichzeichnung von einem abgetasteten bild
GB2067306A (en) * 1980-01-07 1981-07-22 Bell & Howell Co Apparatus for and Methods of Making Bimodal Electrophotographic Copies
EP0084693A1 (fr) * 1982-01-19 1983-08-03 Agfa-Gevaert N.V. Toner fusible pouvant être attiré électrostatiquement
EP0162577A2 (fr) * 1984-04-17 1985-11-27 Hitachi Chemical Co., Ltd. Procédé de production de toners pour l'électrophotographie

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1134622A2 (fr) * 1995-04-07 2001-09-19 Indigo N.V. Toner et substrat plastique
EP1134622A3 (fr) * 1995-04-07 2002-02-06 Indigo N.V. Toner et substrat plastique
US6114077A (en) * 1998-07-31 2000-09-05 Agfa-Gevaert, N.V. White toner composition

Also Published As

Publication number Publication date
DE3771139D1 (de) 1991-08-08
EP0253560B1 (fr) 1991-07-03

Similar Documents

Publication Publication Date Title
US5256507A (en) Method of fusing electrostatographic toners to provide differential gloss
US4657831A (en) Color proofing method and article
CA1332117C (fr) Systeme d'imagerie
EP0233614A2 (fr) Procédé pour la préparation de toners liquides, pour la formation d'images électrostatique, utilisant un additif polaire
US20090297970A1 (en) Toner composition for preventing image blocking
US4758489A (en) Toner for developing latent electrostatic images
US4199356A (en) Electrophotographic process, of transferring a magnetic toner to a copy member having at least 3×1013 ohm-cm resistance
JP3658173B2 (ja) 静電荷像現像用イエロートナー
US4654282A (en) Plural electrophotographic toned image method
US3816117A (en) Multilayer electrophotographic element containing high contrast and opaque barrier layers
EP0720063B1 (fr) Révélateur coloré, agent de développement à deux composants, appareil de formation d'images, méthode de formation d'images colorées et procédé de préparation de révélateurs colorés
US4287282A (en) Composite magnetic developer
EP0253560B1 (fr) Méthode de copiage électrophotographique et papier isolant pour l'utilisation dans cette méthode
JP3403015B2 (ja) 静電荷像現像用マゼンタトナー、二成分系現像剤、カラー画像形成方法及びマゼンタトナーの製造方法
EP0741338B1 (fr) Procédé de formation d'images
JP3210247B2 (ja) 画像形成方法
JPS6385568A (ja) 電子写真用黒色絶縁紙およびそれを用いた電子写真複写方法
WO2013166227A1 (fr) Utilisation de toners fluorescents pour l'imagerie
JPH0654397B2 (ja) 静電荷像現像用トナ−
JPS6385574A (ja) 電子写真用黒色絶縁紙およびそれを用いた電子写真複写方法
JP2599384B2 (ja) 立体感のある複写画像形成方法
JP3287782B2 (ja) 静電荷像現像用イエロートナー及び二成分系現像剤
EP0816928B1 (fr) Image de révelateur résitent à la fêlure
US20030134219A1 (en) Toner composition and fixing method
JPS6385573A (ja) 電子写真用黒色絶縁紙およびそれを用いた電子写真複写方法

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): DE FR GB

17P Request for examination filed

Effective date: 19880408

17Q First examination report despatched

Effective date: 19900314

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE FR GB

REF Corresponds to:

Ref document number: 3771139

Country of ref document: DE

Date of ref document: 19910808

ET Fr: translation filed
RIN2 Information on inventor provided after grant (corrected)

Free format text: KOMURA, SHUJI * HONDA, NOBUYASU * FUJII, MASANORI * ISHITANI, YUSUKE * OGAMI, SHUNSUKE

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 19950627

Year of fee payment: 9

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 19950710

Year of fee payment: 9

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 19950711

Year of fee payment: 9

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Effective date: 19960708

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 19960708

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Effective date: 19970328

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Effective date: 19970402

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST